Early detection of splenic metastasis of lung cancer by18F-2- fluoro-2-deoxyglucose positron emission tomography

Diagnosis of splenic involvement by lung cancer in the early stage is helpful for introducing proper treatment. We report a case of pulmonary adenocarcinoma with splenic metastasis which was first detected by 18F-2-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography (PET). This 56-year-old male underwent left pneumonectomy, extensive lymph node dissection and postoperative adjuvant chemotherapy and radiotherapy. Because progressive elevation of carcinoembryonic antigen was detected 2 years after the operation, whole-body 18F-FDG PET was performed and revealed an 18F-FDG hypermetabolic spot in the splenic hilum. Although subsequent computed tomography (CT) did not reveal any lesions in the spleen, the second and third CT scans performed 10 and 13 months later confirmed the previous PET finding of splenic metastasis. This case suggests that 18F-FDG PET may be useful for early detection of splenic metastasis not visible on CT.